Leaving the IPCC and UNFCCC is Bad for the United States

Mutilateralism matters for normal Americans

You really want to shut that door?

Yesterday, the Trump administration announced via executive order that the United States was withdrawing from 66 international organizations, of which 31 fall under the United Nations (UN).¹ Among these organizations are the Intergovernmental Panel on Climate Change (IPCC) and the UN Framework Convention on Climate Change (UNFCCC).²

Today, I explain a bit about these organizations and why it is contrary to the interests of the U.S. — and also, perhaps surprisingly, the stated interests of the Trump administration — to formally withdraw from each.

Before proceeding, let me acknowledge that there are surely considerable propaganda benefits to the Trump administration of announcing this rejection of multilateralism. Globalists! Woke! Hoax! Similarly, the embrace of these organizations by the Biden administration was also arguably more about propaganda than policy. Existential threat! Threat multiplier! Follow the science!³

On both sides, strong partisans will readily cheerlead along with the rhetoric. However, beyond the news cycle and team sport, there are real world policies with real world impact, including impact on the fortunes of normal Americans.

Today’s post addresses three points:

• The U.S. government — meaning the President and Congress, and both parties when in control of each — has for more than 30 years rejected the UNFCCC as little more than a talking shop, with no real policy teeth. Even so it matters;

• The U.S. helped to create the IPCC in the 1980s to push back against climate activism perceived to contrary to U.S. interests, notably that based on flawed or exaggerated scientific claims. A robust IPCC serves U.S. interests;

• U.S. engagement in multilateral organizations is a source of soft power that has proven meaningful to advance U.S. interests — obviously in economics and defense, but also in 2026 in science as well.

Let’s take a closer look at each.

U.N. Framework Convention on Climate Change

The Trump administration’s withdrawal EO may not actually withdraw the U.S. from the UNFCCC.

It states:

For United Nations entities, withdrawal means ceasing participation in or funding to those entities to the extent permitted by law.

The UNFCCC is technically a “non-self-executing” international agreement. That means that as a signatory, the U.S. has no formal obligations other than those that might come in the aftermath of becoming a signatory, i.e., that Congress and the President together decide to implement in law.

The Congressional Research Service explains:

In cases where treaty provisions are “non-self-executing,” however, implementing legislation may be required to provide U.S. agencies with the domestic legal authority necessary to carry out duties and functions contemplated by the agreement or to make the agreement’s obligations enforceable by private parties in U.S. court.

The U.S. Congress has steadfastly refused to pass any legislation that would turn U.S. participation under the UNFCCC into legal obligations for emissions reductions (or anything else). In January, 2025 the Trump administration announced that the U.S. would no longer contribute funding to the UNFCCC.

The degree and substance of U.S. participation under the UNFCCC has therefore always been at the discretion of the administration in power. Democrats have been more engaged, Republicans less so — however, until now, neither party has ever pushed for participation to be more or less than a talking shop.

Talk can be politically useful, of course. For instance, the Biden administration saw the UNFCCC as a useful tool of international relations, while the Trump administration viewed it as a symbol for exploitation in domestic politics, as with the current EO.

Despite this, there has long been a strong bipartisan consensus in the U.S. that the UNFCCC was never going to lead policy. In 1997, as the Kyoto Protocol to the UNFCCC was being negotiated, the U.S. Senate adopted the Byrd-Hagel resolution that objected to the US adopting binding commitments under the UNFCCC, stating that such commitments:

could result in serious harm to the United States economy, including significant job loss, trade disadvantages, increased energy and consumer costs, or any combination thereof . . .

The vote on that resolution was a resounding 98-0 and effectively scared off all future administrations and Congresses from proposing domestic legislation under the provisions of the UNFCCC.

The result has been the administrative climate policy ping-pong across Democratic and Republican administrations, which has seen executive orders and occasional legislation come and go, but with little discernible effect — US emissions reductions and decarbonization have shown no signs of being changed despite the policy churn, as shown below for the past several decades.

Interestingly, despite the Senate’s ratification of the UNFCCC in 1992, it remains legally unresolved whether or not a president can withdraw from such an agreement unilaterally.

A 2001 report of the Senate Foreign Relations Committee explains:

The constitutional requirements that attend the termination of treaties remain a matter of some controversy. The Senate Foreign Relations Committee has from time to time contended that the termination of treaties requires conjoint action by the President and the Senate (or Congress). But in the most recent instance of open conflict between the President and some Members of the Senate regarding the termination of a treaty—President Carter’s termination of the Mutual Defense Treaty with Taiwan in 1979—the Federal trial and appellate courts reached contrary conclusions regarding the requirements of the Constitution for terminating a treaty and the Supreme Court avoided resolving the constitutional question. . . whether a treaty to be legally as distinguished from effectively terminated requires conjoint action of the political branches remains, as previously indicated, a live issue which the Supreme Court has sidestepped in the past.

While the president’s legal authority to withdraw from the UNFCCC may be an open question, the practical value of doing so is not — the U.S. loses nothing by participating, as it carries with it no obligations, and by collaborating, the U.S. can impart its values into a process that without U.S. participation could move in directions contrary to those values. The result could be policies adopted in other countries or by blocs of countries that are penal to the U.S. — particularly as releated to trade, supply chains, and technology.

Why take that risk?

Intergovernmental Panel on Climate Change

The politics of multilateral scientific organizations are fascinating, and go well beyond today’s post. However, for today’s purposes it is simply necessary to know that such bodies represent important fora for the expression of political influence — by states against states, but perhaps more importantly, by experts against states and states against experts.

In a 2007 recounting of the early development of the IPCC, Michael Oppenheimer of the Environmental Defense Fund and Princeton University explained that he participated in a group of activist scientists who sought to commandeer international scientific organizations in pursuit of political ends related to climate change:

Our group hoped to engage governments and the public in a chain of events that would culminate in a “framework convention”, a type of treaty suggested by the Villach [meeting] participants. To this end, we organized or helped to plan a series of [UN/WMO] science and policy meetings between 1987 and 1990 . . .

These meetings led to calls by the international community — under the legitimizing auspices of the United Nations and World Meteorological Organization — to create an international scientific assessment, modeled on the international assessment of ozone depletion, widely perceived to have been successful.

Oppenheimer continues:

Dr. Moustafa Tolba, the head of UNEP [United Nations Environment Program], had written to then US Secretary of State George Schultz [under GHWB] calling for international action to address climate change. This led to considerable discussion within the US government, WMO, and UNEP. The US government decided that, as a first step, it could support an intergovernmental scientific panel to assess climate change. Facilitated by US support, the IPCC was established at the end of 1988.

Oppenheimer explains that the US supported creation of the IPCC to blunt the impact of activist scientists (emphasis added):

US support was probably critical to IPCC’s establishment. And why did the US government support it? Assistant Undersecretary of State Bill Nitze wrote to me a few years later saying that our group’s activities played a significant role. Among other motivations, the US government saw the creation of the IPCC as a way to prevent the activism stimulated by my colleagues and me from controlling the policy agenda.

One way to look at the IPCC over the 38 years since it has been created is as a forum where scientific claims with political significance have been discussed, arbitrated, and assessed — with some seeing the IPCC assessments as roubust scientific assessments, and others seeing them as resources to convince, coerce, or compel political change, scientific robustness be damned.

As documented at THB extensively in recent years — the IPCC has overall done a very good job in its WG1 playing things straight on the detection and attribution of trends in extreme weather phenomena. At the same time its WG2 is captured by climate advocates, and throughout, the assessment relies heavily on implausible, outdated scenarios.

Without formal participation of the U.S., the chances increase that the IPCC becomes fully captured as an instrument of political advocacy, moving further away from its stated purpose to fairly assess and evaluate the peer reviewed literature. It is easy to imagine the IPCC becoming weaponized against the interests of the U.S., grounded in flawed but seeming authoritative science — This is not speculative, it is already happening.

It would be strongly in the interests of the U.S. not just to participate in the IPCC, but to lead in ways to uphold its scientific integrity and adherence to its orginal mission (here and here). If the IPCC did not exist, we’d have to invent it — so we should make it as robust as possible.

Multilateralism Matters

Importantly, the Trump administration’s EO did not identify global economic institutions to withdraw from — such as the World Bank, IMF, WTO, development banks, etc.. Defense institutions as well. Participation in these organizations is, apparently, deemed to be in the U.S. interest.

It is perhaps easier to make the case why the economy and defense matter for U.S. participation in multilateral organizations. But in 2026, institutions of multilateral science matter just as much — if nothing else, because of their connections to the economy and defense. Consider, that the UNFCCC is closely connected to both trade (e.g., border adjustments, tech transfer) and defense (e.g., critical minerals, supply chains). I’d go further and argue that multilateral science matters on its own (think origins of COVID, as an obvious example).

While the domestic propaganda value of exiting, say, the International Lead and Zinc Study Group (one of the 66 organizations listed in the EO) might arguably exceed its practical or policy value, abandoning the UNFCCC and IPCC is contrary to U.S. interests, including those expressed by the Trump administration.

Participating in and improving these institutions would difficult work. We should try it, not run away. Americans like to say that when things get tough, the tough get going.

Comments welcomed! I especially invite critiques — Why is leaving these institutions a good idea, beyond just symbolism? What is the practical, substantive benefit?

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1. The EO says that the president’s decision to withdraw from these organizations is based on a State Department report: “I have considered the Secretary of State’s report . . .”. I have not seen this report and it does not appear to be public. If THB readers find it please share and I will be happy to discuss.

2. Of note, but beyond the scope of today’s post is the inclusion of IPBES — Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services — on the list.

3. Some THB readers get a bit upset when I am critical of the Trump adminstration. Others get upset when I criticize Democrats. Get over it, there is lots to criticize on both sides and it is my job to do so!